The distribution and the description of the petroglyphs of Mexico, as well as of other forms of pictographs found there, are omitted in the present paper. The subject is so vast, and such a large amount of information has already been given to the public concerning it, that it is not considered in this work, which is mainly devoted to the similar productions of the tribes popularly known as North American Indians, although the pre-Columbian inhabitants of Mexico should, in strictness, be included in that category. It is, however, always to be recognized that one of the most important points in the study of pictographs, is the comparison of those of Mexico with those found farther north. Copies of many petroglyphs found in the eastern hemisphere have been collected, but the limitations of the present paper do not allow of their reproduction or discussion. PETROGLYPHS IN SOUTH AMERICA. While the scope of this work does not contemplate either showing the distribution of the rock carvings in South America, or entering upon any detailed discussion of them, some account is here subjoined for the purpose of indicating the great extent of the ethnic material of this character that is yet to be obtained from that continent. Alexander von Humboldt, in Aspects of Nature in different lands and different climates, etc., Vol. I, pp. 196-201, London, 1850, gives the following general remarks concerning pictographs from South America: In the interior of South America, between the 2d and 4th degrees of North latitude, a forest-covered plain is enclosed by four rivers, the Orinoco, the Atabapo, the Rio Negro, and the Cassiquiare. In this district are found rocks of granite and of syenite, covered, like those of Caicara and Uruana, with colossal symbolical figures of crocodiles and tigers, and drawings of household utensils, and of the sun and moon. At the present time this remote corner of the earth is entirely without human inhabitants, throughout an extent of more than 8,000 square geographical miles. The tribes nearest to its boundaries are wandering naked savages, in the lowest stages of human existence, and far removed from any thoughts of carving hieroglyphics on rocks. One may trace in South America an entire zone, extending through more than eight degrees of longitude, of rocks so ornamented; viz. from the Rupuniri, Essequibo, and the mountains of Pacaraima, to the banks of the Orinoco and of the Yupura. These carvings may belong to very different epochs, for Sir Robert Schomburgk even found on the Rio Negro representations of a Spanish galiot, which must have been of a later date than the beginning of the 16th century; and this in a wilderness where the natives were probably as rude then as at the present time. But it must not be forgotten that * * nations of very different descent, when in a similar uncivilized state, having the same disposition to